Inflammatory Myofibroblastic Tumor (plasma cell granuloma): Clinicopathologic Study of 20 Cases with Immunohistochemical and Ultrastructural Observations

Abstract

Twenty cases of inflammatory myofibroblastic tumor (IMT) were studied; 19 involved the lung and 1 the esophagus only. The patients' ages ranged from 3 to 72 years. There were 9 males and 11 females. Involvement of a bronchus was seen in one case and of mediastinal structures in four. Chest pain and dyspnea were common symptoms; eight patients were asymptomatic. Seven patients underwent lobectomy, 12 local excision, and 1 biopsy alone. The lesions were nonencapsulated and ranged from 1.2 to 15 cm. Various proportions of plasma cells, histiocytes, and spindle cells were observed; the latter corresponded ultrastructurally to fibroblasts and myofibroblasts, were immunoreactive for vimentin and actin and focally for desmin, and were negative for epithelial markers. Plasma cells were polyclonal for light chains. One patient had two recurrences, and in one case a large pleural IMT was found eight years after the excision of a similar lesion in the lung. All patients with follow-up (ten) were well as long as ten years after the diagnosis (average, 3.7 years).

Plexiform Angiomyxoid Myofibroblastic Tumor of the Stomach

“…However, we think that the "myofibroblastic" designation is not necessarily inappropriate, because myofibroblastic tumor cells are predominant in the majority of the reported cases. For example, inflammatory myofibroblastic tumors may also contain fibroblastic components as determined using ultrastructural analysis [18,19] , and focally express desmin and calponin in 60%-70% of cases [18,20] . Miettinen et al [15] proposed that this tumor should be designated as "plexiform fibromyxoma" based on the plexiform architecture and combination of myxoid and fibromyxoid elements.…”

Anaplastic lymphoma kinase (ALK 1) staining and molecular analysis in inflammatory myofibroblastic tumours of the bladder: a preliminary clinicopathological study of nine cases and review of the literature

“…Clinical presentation is usually as a mass lesion, with symptoms of pain, fever and weight loss and haematological findings of anaemia, thrombocytosis, increased erythrocyte sedimentation rate (ESR) and raised gamma globulins. 12 Three main microscopic patterns are recognised in IMFT: (1) loose stellate cells with a myxoid background including scattered inflammatory cells (nodular fasciitis-like), (2) spindle cells with a compact fascicular pattern, and (3) sparsely cellular collagenised area, and these may be present within the same case. 11 As a result of endoscopic and microscopic features, including size, presence of atypical spindle cells, scattered mitoses and an 'infiltrative' margin, these entities may be mistaken for malignant spindle cell lesions and the differentials considered vary with the site of the lesion.…”

Fever of Unknown Origin as a Presentation of Gastric Inflammatory Myofibroblastic Tumor in a Two-Year-Old Boy

“…IMT is confirmed by the finding of a stroma with mature spindle cells, often arranged in whorls with fibrous bands. Mixed throughout the lesion is an inflammatory infiltration consisting predominantly of plasma cells but often lymphocytes, histiocytes, and occasionally a small component of acute inflammatory cells (17). Immunohistologically, the spindle cells are reactive against antibodies to vimentin, smooth muscle actin, and muscle-specific protein in a majority of cases (2) as well as in ours.…”